WQ 3 will be followed by an all-new episode, Tower Fall, which will be DLC and will take the story of your pack through the summer and fall.

Should I buy the game now or wait for WQ 3?

No need to wait to buy the game. WolfQuest 3 will be a free update to players who own WolfQuest 2.7. If you are buying WQ 3 for the first time in 2018, the cost will likely be more than than the current game 2.7 (so cheaper to purchase it now and get WQ 3 as a free update). Get the game